Iptables inicializācijas skripts

1. Izveido init skriptu:

   sudo touch /etc/init.d/iptables
   sudo chmod 755 /etc/init.d/iptables

2. sudo gedit /etc/init.d/iptables

   un ieliek tajā sekojošu saturu:

   #!/bin/sh
   # see: http://ubuntuforums.org/showthread.php?t=19106
   #This is a ubuntu adapted iptables script from gentoo
   #(http://www.gentoo.org) which was originally distributed
   # under the terms of the GNU General Public License v2
   #and was Copyrighted 1999-2004 by the Gentoo Foundation
   #
   #This adapted version was intended for and ad-hoc personal
   #situation and as such no warranty is provided.
   
   IPTABLES_SAVE="/etc/default/iptables-rules"
   SAVE_RESTORE_OPTIONS="-c"
   SAVE_ON_STOP="yes"
   
   checkrules() {
     if [ ! -f ${IPTABLES_SAVE} ]
     then
       echo "Not starting iptables. First create some rules then run"
       echo "\"/etc/init.d/iptables save\""
       return 1
     fi
   }
   
   save() {
     echo "Saving iptables state"
     /sbin/iptables-save ${SAVE_RESTORE_OPTIONS} > ${IPTABLES_SAVE}
   }
   
   start(){
     checkrules || return 1
       echo  "Loading iptables state and starting firewall"
       echo -n "Restoring iptables ruleset"
       # Enable forwarding (if necessary)
       echo 1 >/proc/sys/net/ipv4/ip_forward
       start-stop-daemon --start --quiet --exec /sbin/iptables-restore -- ${SAVE_RESTORE_OPTIONS} < ${IPTABLES_SAVE}
   }
   
   case "$1" in
     save)
           save
           echo "."
           ;;
   
     start)
       start
     echo "."
     ;;
     stop)
       if [ "${SAVE_ON_STOP}" = "yes" ]; then
         save || exit 1
       fi
       echo -n "Stopping firewall"
       for a in `cat /proc/net/ip_tables_names`; do
         /sbin/iptables -F -t $a
         /sbin/iptables -X -t $a
   
         if [ $a == nat ]; then
           /sbin/iptables -t nat -P PREROUTING ACCEPT
           /sbin/iptables -t nat -P POSTROUTING ACCEPT
           /sbin/iptables -t nat -P OUTPUT ACCEPT
         elif [ $a == mangle ]; then
           /sbin/iptables -t mangle -P PREROUTING ACCEPT
           /sbin/iptables -t mangle -P INPUT ACCEPT
           /sbin/iptables -t mangle -P FORWARD ACCEPT
           /sbin/iptables -t mangle -P OUTPUT ACCEPT
           /sbin/iptables -t mangle -P POSTROUTING ACCEPT
         elif [ $a == filter ]; then
           /sbin/iptables -t filter -P INPUT ACCEPT
           /sbin/iptables -t filter -P FORWARD ACCEPT
           /sbin/iptables -t filter -P OUTPUT ACCEPT
         fi
       done
       start-stop-daemon --stop --quiet --pidfile /var/run/iptables.pid --exec /sbin/iptables
       echo "."
       ;;
   
     restart)
       echo -n "Flushing firewall"
         for a in `cat /proc/net/ip_tables_names`; do
           /sbin/iptables -F -t $a
             /sbin/iptables -X -t $a
         done;
       start
       echo "."
       ;;
     *)
       echo "Usage: /etc/init.d/iptables {start|stop|restart|save}" >&2
       exit 1
       ;;
   esac
   
   exit 0

3. Pievieno init skripta izsaukumu:

   sudo update-rc.d iptables start 37 S . stop 37 0 .

4. Saglabā tekošos iestatījumus:

   /etc/init.d/iptables save

5. Pārstartē iptables:

   /etc/init.d/iptables restart